目的对儿童体重指数(body mass index,BMI)与肠道菌群多样性的关联性进行初步探讨。方法采用横断面调查方法,从2018年7月1日至7日在广东省茂名市共招募87名儿童,平均年龄(11±2)岁。以世界卫生组织2006年发布的儿童体格生长指标百...目的对儿童体重指数(body mass index,BMI)与肠道菌群多样性的关联性进行初步探讨。方法采用横断面调查方法,从2018年7月1日至7日在广东省茂名市共招募87名儿童,平均年龄(11±2)岁。以世界卫生组织2006年发布的儿童体格生长指标百分位数参考值为标准,将研究对象分成偏瘦、正常、超重以及肥胖4个组。通过Illumina Miseq高通量测序方法,对粪便样本细菌16S V4~V5区进行碱基测序;采用广义线性模型分析儿童BMI与Chao、Ace、Shannon以及Simpson指数等肠道菌群Alpha多样性指标的相关性。结果BMI每升高1 kg/m^(2),肥胖儿童的Shannon指数降低1.31%(95%CI:-2.31%~-0.25%),Simpson指数上升3.89%(95%CI:1.01%~6.83%);而偏瘦儿童的Ace指数下降4.27%(95%CI:-8.14%~-0.24%)。此外,趋势性检验结果显示,随BMI四分位数的增加,Shannon指数呈下降趋势(P=0.042)。结论儿童BMI与肠道菌群多样性存在关联,且随着BMI的增加,肠道菌群多样性呈下降趋势。此外,不同体型儿童中BMI与肠道菌群的关联强度可能不同。展开更多
ABB公司DCS系统使用了MB300网络和800XA系统。包括四台A C450控制器和一台A C800M控制器。运行中出现操作员站画面卡顿、数据显示异常问题。针对该通讯故障问题,从网络通讯电缆、网关、服务器等可能引起故障的各个方面进行了排查、优化...ABB公司DCS系统使用了MB300网络和800XA系统。包括四台A C450控制器和一台A C800M控制器。运行中出现操作员站画面卡顿、数据显示异常问题。针对该通讯故障问题,从网络通讯电缆、网关、服务器等可能引起故障的各个方面进行了排查、优化、处理,最终解决了问题。对涉及的硬件软件的功能、检查的步骤、参数、程序等进行了详细地阐述,对A B B DCS系统网络故障排查处理具有很强的指导意义。展开更多
Trans-Eurasian exchange along the Ancient Silk Road The Ancient Silk Road was the major passageway for linking China,Central and West Asia,and Europe between the second century BCE(Before Common Era)and the sixteenth ...Trans-Eurasian exchange along the Ancient Silk Road The Ancient Silk Road was the major passageway for linking China,Central and West Asia,and Europe between the second century BCE(Before Common Era)and the sixteenth CE,which is identified as the center of civilizations in the Old World during that period(Frankopan,2015).展开更多
In a GPS illuminator based passive radar system,estimation of direction of arriving(DOA) of multiple targets is a difficult problem due to strong interference.A two-stage method combining extensive cancellation algori...In a GPS illuminator based passive radar system,estimation of direction of arriving(DOA) of multiple targets is a difficult problem due to strong interference.A two-stage method combining extensive cancellation algorithm(ECA) and sparse representation is proposed.In the first stage,ECA algorithm is used to eliminate the direct-path and multi-path interference.In the second stage,sparse representation of improved weight constraints based on L1 norm is adopted to estimate DOA and suppress the interference.Simulation results show that the proposed method can effectively estimate DOA in low computation complexity without estimating the disturbance parameter.展开更多
Significant spatiotemporal variation in human livelihood patterns and its relationship to trans-Eurasian exchange and climate change in north China during the late Neolithic and Bronze Age, has been intensively studie...Significant spatiotemporal variation in human livelihood patterns and its relationship to trans-Eurasian exchange and climate change in north China during the late Neolithic and Bronze Age, has been intensively studied in recent years, but the comprehensive influence of natural and social factors on this variation is not well understood. Therefore, we analyze archaeobotanical, zooarchaeological and carbon isotopic data from late Neolithic and Bronze Age sites in agricultural, pastoral, and agro-pastoral regions of north China. Our results demonstrate human subsistence strategies transformed at different speeds in these three geographic areas after wheat, barley, and sheep, goats, and cattle were introduced into north China. Introduced crops and livestock dominated human livelihoods in pastoral regions and became important subsistence in areas above ~1500 m a.s.l. in agro-pastoral regions after ~3600 BP. In agricultural regions, indigenous millet crops were the most important subsistence throughout 6000– 2200 BP, but wheat use increased significantly around 2700 BP. Our study suggests that the introduction of new crops and herbivorous livestock related to the prehistoric trans-Eurasian exchange, and their adaptive advantage in high-cold environments might have rapidly facilitated human adaptability and social development in pastoral regions and northwest margin of agro-pastoral regions during the Bronze Age.展开更多
文摘ABB公司DCS系统使用了MB300网络和800XA系统。包括四台A C450控制器和一台A C800M控制器。运行中出现操作员站画面卡顿、数据显示异常问题。针对该通讯故障问题,从网络通讯电缆、网关、服务器等可能引起故障的各个方面进行了排查、优化、处理,最终解决了问题。对涉及的硬件软件的功能、检查的步骤、参数、程序等进行了详细地阐述,对A B B DCS系统网络故障排查处理具有很强的指导意义。
文摘Trans-Eurasian exchange along the Ancient Silk Road The Ancient Silk Road was the major passageway for linking China,Central and West Asia,and Europe between the second century BCE(Before Common Era)and the sixteenth CE,which is identified as the center of civilizations in the Old World during that period(Frankopan,2015).
基金Supported by the National Natural Science Foundation of China(No.31270737)Specialized Research Fund for the Doctoral Program of Higher Education(No.20110062110002)the Fundamental Research Funds for the Central Universities(No.2572014EB03,DL13BB16)
文摘In a GPS illuminator based passive radar system,estimation of direction of arriving(DOA) of multiple targets is a difficult problem due to strong interference.A two-stage method combining extensive cancellation algorithm(ECA) and sparse representation is proposed.In the first stage,ECA algorithm is used to eliminate the direct-path and multi-path interference.In the second stage,sparse representation of improved weight constraints based on L1 norm is adopted to estimate DOA and suppress the interference.Simulation results show that the proposed method can effectively estimate DOA in low computation complexity without estimating the disturbance parameter.
基金National Natural Science Foundation of China,No.41825001NSFC-INSF Joint Research Project,No.42261144670+1 种基金Academician and Expert Workstation of Yunnan Province,No.202305AF150183European Research Council,No.ERC-2019-ADG 883700-TRAM。
文摘Significant spatiotemporal variation in human livelihood patterns and its relationship to trans-Eurasian exchange and climate change in north China during the late Neolithic and Bronze Age, has been intensively studied in recent years, but the comprehensive influence of natural and social factors on this variation is not well understood. Therefore, we analyze archaeobotanical, zooarchaeological and carbon isotopic data from late Neolithic and Bronze Age sites in agricultural, pastoral, and agro-pastoral regions of north China. Our results demonstrate human subsistence strategies transformed at different speeds in these three geographic areas after wheat, barley, and sheep, goats, and cattle were introduced into north China. Introduced crops and livestock dominated human livelihoods in pastoral regions and became important subsistence in areas above ~1500 m a.s.l. in agro-pastoral regions after ~3600 BP. In agricultural regions, indigenous millet crops were the most important subsistence throughout 6000– 2200 BP, but wheat use increased significantly around 2700 BP. Our study suggests that the introduction of new crops and herbivorous livestock related to the prehistoric trans-Eurasian exchange, and their adaptive advantage in high-cold environments might have rapidly facilitated human adaptability and social development in pastoral regions and northwest margin of agro-pastoral regions during the Bronze Age.
